/**
* Read the envelope based upon the indicator value
*
* @param envelopeIndicator
* @param reader
* @return
*/
private GeometryEnvelope readEnvelope(int envelopeIndicator, ByteReader reader) {
GeometryEnvelope envelope = null;
if (envelopeIndicator > 0) {
// Read x and y values and create envelope
double minX = reader.readDouble();
double maxX = reader.readDouble();
double minY = reader.readDouble();
double maxY = reader.readDouble();
boolean hasZ = false;
Double minZ = null;
Double maxZ = null;
boolean hasM = false;
Double minM = null;
Double maxM = null;
// Read z values
if (envelopeIndicator == 2 || envelopeIndicator == 4) {
hasZ = true;
minZ = reader.readDouble();
maxZ = reader.readDouble();
}
// Read m values
if (envelopeIndicator == 3 || envelopeIndicator == 4) {
hasM = true;
minM = reader.readDouble();
maxM = reader.readDouble();
}
envelope = new GeometryEnvelope(hasZ, hasM);
envelope.setMinX(minX);
envelope.setMaxX(maxX);
envelope.setMinY(minY);
envelope.setMaxY(maxY);
if (hasZ) {
envelope.setMinZ(minZ);
envelope.setMaxZ(maxZ);
}
if (hasM) {
envelope.setMinM(minM);
envelope.setMaxM(maxM);
}
}
return envelope;
}
/**
* Populate the geometry data from the bytes
*
* @param bytes
*/
public void fromBytes(byte[] bytes) {
this.bytes = bytes;
ByteReader reader = new ByteReader(bytes);
// Get 2 bytes as the magic number and validate
String magic = null;
try {
magic = reader.readString(2);
} catch (UnsupportedEncodingException e) {
throw new GeoPackageException(
"Unexpected GeoPackage Geometry magic number character encoding: Expected: "
+ GeoPackageConstants.GEO_PACKAGE_GEOMETRY_MAGIC_NUMBER);
}
if (!magic.equals(GeoPackageConstants.GEO_PACKAGE_GEOMETRY_MAGIC_NUMBER)) {
throw new GeoPackageException(
"Unexpected GeoPackage Geometry magic number: "
+ magic
+ ", Expected: "
+ GeoPackageConstants.GEO_PACKAGE_GEOMETRY_MAGIC_NUMBER);
}
// Get a byte as the version and validate, value of 0 = version 1
byte version = reader.readByte();
if (version != GeoPackageConstants.GEO_PACKAGE_GEOMETRY_VERSION_1) {
throw new GeoPackageException(
"Unexpected GeoPackage Geometry version: "
+ version
+ ", Expected: "
+ GeoPackageConstants.GEO_PACKAGE_GEOMETRY_VERSION_1);
}
// Get a flags byte and then read the flag values
byte flags = reader.readByte();
int envelopeIndicator = readFlags(flags);
reader.setByteOrder(byteOrder);
// Read the 5th - 8th bytes as the srs id
srsId = reader.readInt();
// Read the envelope
envelope = readEnvelope(envelopeIndicator, reader);
// Save off where the WKB bytes start
wkbGeometryIndex = reader.getNextByte();
// Read the Well-Known Binary Geometry if not marked as empty
if (!empty) {
geometry = WkbGeometryReader.readGeometry(reader);
}
}
